计及逆变型分布式电源输出特性的配电网自适应电流保护研究

分布式电源输出的间歇性、非线性特点给配电网的继电保护配置与整定带来很大困难,考虑配电网结构的复杂性以及通信设备覆盖全网的高成本问题,需要研究仅利用保护本地信息进行保护自适应整定的方法。分析并建立了逆变型分布式电源的输出特性方程,通过求解故障前分布式电源运行点获取分布式电源的实时输出特性,针对下游保护研究并提出基于本地信息进行自适应电流保护整定的原理及方法。该方法能够不依赖于通信,准确获取逆变型分布式电源的实时运行参数,从而提高电流保护整定的可靠性。提出的方法能够在保护定值整定过程中准确计及分布式电源的输出,对于降低保护配置成本、提高保护整定的可靠性具有重要意义。

Research on Adaptive Current Protection for Distribution Network Considering the Output Characteristics of Inverter-interfaced Distributed Generator

The intermittent and nonlinear characteristics of the distributed generator make it difficult to configure and set the relay protection of the distribution network.Considering the complexity of distribution network structure and the high cost of communication equipment covering the whole network,it is necessary to study the protection adaptive setting method using only local information.In this paper,the output characteristics of inverter interfaced distributed generator is analyzed.The method of calculating the running point for distributed generator before the fault occurs based on local information is proposed,the principle and method of self-adaptive current protection are proposed.This method is independent of communication,and can accurately obtain the real-time operating parameters of the distributed generator,thereby improving the reliability of current protection setting.With the method in this paper,the output of distributed generator can be accurately taken into account in the process of setting the value of protection,which is of great significance to reduce the cost of protection configuration and improve the reliability of protection setting.